An avalanche on Mount Everest early Friday killed twelve people and left three more critically injured. Four other climbers are currently unaccounted for.
The Guardianreports that the avalanche occurred just above base camp as a Sherpa work crew was preparing ropes along the popular South Col climbing route. Rescue crews retrieved twelve bodies and evacuated the injured to Kathmandu for medical treatment. Search efforts continue for the rest of the missing climbers.
The accident comes right at the start of the busy spring season when hundreds of mountaineers arrive in camp to acclimate and make summit bids during a historically favorable weather window in mid-May. Over 300 foreign climbers have been granted permits for this season and will hire an estimated 400 local Sherpa guides, CNN reports.
Before Friday, the single-deadliest day on Everest occurred in 1996 when eight climbers disappeared in a storm near the summit. A total of eight climbers died on the mountain in 2013.